Analog Devices

The LTC4050-4.1/LTC4050-4.2 are complete standalone constant-current/constant-voltage linear charge controllers for lithium-ion (Li-Ion) batteries. Charge current is programmable and final float voltage has ±1% accuracy.When the input supply is removed, the LTC4050 automatically enters a low quiescent current sleep mode, dropping the battery drain current to 5µA. An internal comparator detects the near-end-of-charge (C/10) condition while a programmable timer, using an external capacitor, sets the total charge time. Fully discharged cells are automatically trickle charged at 10% of the programmed current until cell voltage exceeds 2.49V. The thermistor interface suspends charging if the cell temperature is outside of a 0°C to 50°C temperature window.The LTC4050 begins a new charge cycle when a discharged battery is connected to the charger or when the input power is applied. In addition, a new charge cycle is automatically started if the battery remains connected to the charger and the cell voltage drops below 3.88V for 4.1V cells or below 3.98V for 4.2V cells.The LTC4050 is available in the 10-pin MSOP package.ApplicationsCellular PhonesHandheld ComputersCharging Docks and Cradles

The LTC4053 is a standalone linear charger for lithium-ion batteries that can be powered directly from a USB port. The IC contains an on-chip power MOSFET and eliminates the need for an external sense resistor and blocking diode. Thermal regulation automatically adjusts charge current to limit die temperature during high power or high ambient temperature conditions. This feature protects the end product and the LTC4053 from thermal stress while the IC charges the battery at maximum rate without interruption.The charge current and charge time can be set externally with a single resistor and capacitor, respectively. When the input supply (wall adapter or USB supply) is removed, the LTC4053 automatically enters a low current sleep mode, dropping the battery drain current to less than 5µA.The LTC4053 also includes NTC temperature sensing, C/10 detection circuitry, AC present logic, low battery charge conditioning (trickle charging) and shutdown (25µA supply current).The LTC4053 is available in a 10-pin thermally enhanced MSOP package.ApplicationsCellular TelephonesHandheld ComputersCharging Docks and CradlesMP3 PlayersDigital Cameras

The LTC4054 is a complete constant-current/constant-voltage linear charger for single cell lithium-ion batteries. Its ThinSOT package and low external component count make the LTC4054 ideally suited for portable applications. Furthermore, the LTC4054 is specifically designed to work within USB power specifications.No external sense resistor is needed, and no blocking diode is required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature. The charge voltage is fixed at 4.2V, and the charge current can be programmed externally with a single resistor. The LTC4054 automatically terminates the charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached.When the input supply (wall adapter or USB supply) is removed, the LTC4054 automatically enters a low current state, dropping the battery drain current to less than 2µA. The LTC4054 can be put into shutdown mode, reducing the supply current to 25µA.Other features include charge current monitor, undervoltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage.Max Charge CurrentTrickle ChargeLTC4054-4.2800mAYesLTC4054X-4.2800mANoLTC4054L-4.2150mAYesApplicationsCellular Telephones, PDAs, MP3 PlayersCharging Docks and CradlesBluetooth Applications

The LTC4055/LTC4055-1 are USB power manager and Li-Ion battery chargers designed to work in portable battery-powered applications. The parts manage and limit the total current used by the USB peripheral for operation and battery charging. Depending on the state of the current select pin (HPWR), total input current can be limited to either 100mA or 500mA. The voltage drop from the USB supply or battery to the USB peripheral is typically less than 100mV at 400mA and 20mV at 80mA. Other management features include: automatic switch over to battery when input is removed, inrush current limiting, reverse current blocking, undervoltage lockout and thermal shutdown.The LTC4055/LTC4055-1 include a complete constant-current/constant-voltage linear charger for single cell Li-ion batteries. The float voltage applied to the battery is held to a tight 0.8% tolerance, and charge current is programmable using an external resistor to ground. Fully discharged cells are automatically trickle charged at 10% of the programmed current until the cell voltage exceeds 2.8V. Total charge time is programmable by an external capacitor to ground. When the battery drops 100mV below the float voltage, automatic recharging of the battery occurs. Also featured is an NTC thermistor input used to monitor battery temperature while charging.The LTC4055/LTC4055-1 are available in a 16-pin low profile (4mm x 4mm) QFN package.ApplicationsPortable USB Devices: Cameras, MP3 Players, PDAs

The LTC4056 is a low cost, single-cell, constant-current/ constant-voltage Li-Ion battery charger controller with a programmable termination timer. When combined with a few external components, the LTC4056 forms a very small standalone charger for single cell lithium-ion batteries.Charge current and charge time are set externally with a single resistor and capacitor, respectively. The LTC4056 charges to a final float voltage accurate to ±0.6%. Manual shutdown is accomplished by grounding the TIMER/SHDNpin, while removing input power automatically puts the LTC4056 into a sleep mode. Both the shutdown and sleep modes drain near zero current from the battery; the shutdown mode reduces supply current to 40µA.The output driver is both current limited and thermally protected to prevent operating outside of safe limits. No external blocking diode or sense resistor is required. The LTC4056 also includes low battery charge conditioning (trickle charging), undervoltage charge current limiting, automatic recharge and a charge status output.The LTC4056 is available in a low profile (1mm) 8-lead SOT-23 (ThinSOT™) package.ApplicationsCellular TelephonesHandheld ComputersDigital CamerasCharging Docks and CradlesLow Cost and Small Size Chargers

The LTC4057 is a constant-current/constant-voltage linear charger for single-cell lithium-ion batteries. Its ThinSOT™package and low external component count make the LTC4057 especially well suited for portable applications. Furthermore, the LTC4057 is specifically designed to work within USB power specifications.No external sense resistor is needed and no blocking diode is required due to the internal MOSFET architecture. Thermal feedback prevents overheating by regulating the charge current to limit the die temperature during high power operation or high ambient temperature conditions. The charge voltage is preset at 4.2V and the charge current can be programmed externally with a single resistor.When the input supply (wall adapter or USB supply) is removed, the LTC4057 automatically enters a low current state, dropping the battery drain current to less than 2µA. With power applied, the LTC4057 can be put into shutdown mode, reducing the supply current to 25µA.For the standalone version (on-board charge termination) of the LTC4057, refer to the LTC4054.ApplicationsWireless PDAsCellular PhonesPortable Electronics

The LTC4058 is a complete constant-current/constant voltage linear charger for single cell lithium-ion batteries. Its DFN package and low external component count make the LTC4058 ideally suited for portable applications. Furthermore, the LTC4058 is designed to work within USB power specifications.The LTC4058 can Kelvin sense the battery terminal for more accurate float voltage charging. No external sense resistor or external blocking diode are required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature conditions. The charge voltage is fixed at 4.2V and the charge current is programmed with a resistor. The LTC4058 terminates the charge cycle when the charge current drops to 10% of the programmed value after the final float voltage is reached.When the input supply (wall adapter or USB supply) is removed, the LTC4058 enters a low current state dropping the battery drain current to less than 2µA. Other features include charge current monitor, undervoltage lockout, automatic recharge and status pins to indicate charge termination and the presence of an input voltage.*US Patent 6,522,118ApplicationsCellular Telephones, PDAs, MP3 PlayersBluetooth Applications